Light emitting device, display unit, and illumination unit

ABSTRACT

A light emitting device includes: a light source; an optical component including a light incident surface, the light incident surface facing the light source; and a wavelength conversion member provided between the light source and the light incident surface, the wavelength conversion member crossing a first region and extending to a second region outside the first region, the first region being surrounded by the light incident surface and light paths of light that is emitted from the light source and enters edges of the light incident surface.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent ApplicationNo. JP 2012-090213 filed in the Japanese Patent Office on Apr. 11, 2012,the entire content of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a light emitting device favorable fora surface light source, and to a display unit and an illumination unitthat each include the light emitting device.

A surface-emitting device that uses a blue light emitting diode (LED) isemployed, for example, in a backlight of a liquid crystal display unitor in an illumination unit. For example, Japanese Patent No. 3116727discloses to obtain white light by providing a film to which afluorescent material is applied to a light emission observation surfaceof a light guide plate and converting, by the fluorescent material, awavelength of the light entering the light guide plate from a blue LED.Moreover, for example, Japanese Patent No. 3114805 discloses to providea wavelength converter, in which a fluorescent material is mixed with anelastic body, between a blue LED and an end face of a light guide plate.

SUMMARY

In general, it is strongly desired to increase evenness of color in aplane in a light emitting device that is used as a surface light source.

It is desirable to provide a light emitting device capable of increasingevenness of color in a plane, and to provide a display unit and anillumination unit that each include the light emitting device.

According to an embodiment of a present disclosure, there is provided alight emitting device including: a light source; an optical componentincluding a light incident surface, the light incident surface facingthe light source; and a wavelength conversion member provided betweenthe light source and the light incident surface, the wavelengthconversion member crossing a first region and extending to a secondregion outside the first region, the first region being surrounded bythe light incident surface and light paths of light that is emitted fromthe light source and enters edges of the light incident surface.

In the light emitting device according to the embodiment of the presentdisclosure, light emitted from the light source is subjected towavelength conversion in the wavelength conversion member, enters thelight incident surface of the optical component, travels through theinside of the optical component, and exits from a light emittingsurface. This is observed as light emission. Here, the wavelengthconversion member crosses the first region surrounded by the lightincident surface and the light paths of the light being emitted from thelight source and entering the edges of the light incident surface, andextends to the second region outside the first region. This reduceslight that does not pass through the wavelength conversion member out ofthe light emitted from the light source. In other words, this reduceslight that is not subjected to wavelength conversion in the wavelengthconversion member.

According to an embodiment of the present disclosure, there is provideda display unit with a liquid crystal panel and a light emitting deviceon a back face side of the liquid crystal panel, the light emittingdevice including: a light source; an optical component including a lightincident surface, the light incident surface facing the light source;and a wavelength conversion member provided between the light source andthe light incident surface, the wavelength conversion member crossing afirst region and extending to a second region outside the first region,the first region being surrounded by the light incident surface andlight paths of light that is emitted from the light source and entersedges of the light incident surface.

In the display unit according to the embodiment of the presentdisclosure, the light emitted from the light emitting device isselectively transmitted by the liquid crystal panel and an image isdisplayed thereby.

According to an embodiment of the present disclosure, there is providedan illumination unit with a light emitting device, the light emittingdevice including: a light source; an optical component including a lightincident surface, the light incident surface facing the light source;and a wavelength conversion member provided between the light source andthe light incident surface, the wavelength conversion member crossing afirst region and extending to a second region outside the first region,the first region being surrounded by the light incident surface andlight paths of light that is emitted from the light source and entersedges of the light incident surface.

In the illumination unit according to the embodiment of the presentdisclosure, illumination is performed with light emitted from the lightemitting device.

According to the light emitting device of the embodiment of the presentdisclosure, the wavelength conversion member crosses the first regionsurrounded by the light incident surface and the light paths of thelight entering the edges of the light incident surface and extends tothe second region outside the first region. Therefore, evenness of colorin a plane is increased. According to each of the display unit and theillumination unit of the embodiments of the present disclosure, thelight emitting device of the embodiment of the present disclosure isincluded. Therefore, high quality in display or in illumination isachieved.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of thetechnology.

FIG. 1 is a perspective view illustrating a general configuration of alight emitting device according to a first embodiment of the presentdisclosure.

FIG. 2 is a cross-sectional view illustrating an arrangementrelationship between a light source, a light guide plate, and awavelength conversion member shown in FIG. 1.

FIG. 3 is a perspective view illustrating beams of light that travelfrom the light source shown in FIG. 2 toward a light incident surface ofthe light guide plate shown in FIG. 2.

FIG. 4 is a cross-sectional view illustrating a configuration of a lightemitting device according to a second embodiment of the presentdisclosure.

FIG. 5 is a cross-sectional view for explaining an example that does notinclude a light shielding member.

FIG. 6 is a plan view schematically illustrating a light emission stateof the light emitting device shown in FIG. 5.

FIG. 7 is a cross-sectional view illustrating an example of dimensionsof the light emitting device shown in FIG. 5.

FIG. 8 is a cross-sectional view illustrating a portion that emits bluelight in the light emitting device with the dimensions shown in FIG. 7.

FIG. 9 is a cross-sectional view illustrating a modification of thelight emitting device shown in FIG. 4.

FIG. 10 is a cross-sectional view illustrating another modification ofthe light emitting device shown in FIG. 4.

FIG. 11 is a cross-sectional view illustrating still anothermodification of the light emitting device shown in FIG. 4.

FIG. 12 is a cross-sectional view illustrating still anothermodification of the light emitting device shown in FIG. 4.

FIG. 13 is a perspective view illustrating an appearance of a displayunit according to a third embodiment of the present disclosure.

FIG. 14 is a perspective exploded view illustrating a main body partshown in FIG. 13.

FIG. 15 is a perspective exploded view illustrating a panel module shownin FIG. 14.

FIGS. 16A and 16B are perspective views each illustrating an appearanceof an application example 1 of the display unit.

FIG. 17 is a perspective view illustrating an appearance of anapplication example 2.

FIGS. 18A and 18B are perspective views illustrating an appearance of anapplication example 3 seen from the front and from the back,respectively.

FIG. 19 is a perspective view illustrating an appearance of anapplication example 4.

FIG. 20 is a perspective view illustrating an appearance of anapplication example 5.

FIGS. 21A and 21B are a front view and a side view of an applicationexample 6 in an open state, respectively, and FIGS. 21C to 21G are afront view, a left side view, a right side view, a top view, and abottom view of the application example 6 in a closed state,respectively.

FIG. 22 is a perspective view illustrating an appearance of anapplication example 7 of an illumination unit.

FIG. 23 is a perspective view illustrating an appearance of anapplication example 8 of the illumination unit.

FIG. 24 is a perspective view illustrating an appearance of anapplication example 9 of the illumination unit.

DETAILED DESCRIPTION

Preferred embodiments of the present disclosure will be hereinafterdescribed in detail with reference to the attached drawings. Descriptionwill be given in the following order.

1. First Embodiment (light emitting device; an example in which awavelength conversion member crosses a region surrounded by a lightincident surface and light paths of light being emitted from a lightsource and entering edges of the light incident surface, and thewavelength conversion member extends to a region outside this region)

2. Second Embodiment (light emitting device; an example in which a lightshielding member is provided on a light path of light that is emittedfrom the light source, passes through a container without passingthrough the wavelength conversion member, and travels toward a surfaceadjacent to the light incident surface of the light guide plate)

3. Third Embodiment (display unit; liquid crystal display unit)

4. Application Examples 1 to 6 of Display Unit

5. Application Examples 7 to 9 of Illumination Unit

First Embodiment

FIG. 1 illustrates a general configuration of a light emitting device(light emitting device 1) according to a first embodiment of the presentdisclosure. The light emitting device 1 may be used, for example, as abacklight that illuminates a transmissive liquid crystal panel from theback thereof, or as an illumination unit, for example, in a room. Thelight emitting device 1 includes a light source 10, a light guide plate20, a wavelength conversion member 30, a reflection member 40, and anoptical sheet 50. The light guide plate 20 corresponds to a specific butnot limitative example of “optical component” of the present disclosure.

In the present specification, a lamination direction of the opticalsheet 50, the light guide plate 20, and the reflection member 40 isreferred to as “Z direction (front-back direction)”, a lateral directionin a main surface (largest surface) of the guide plate 20 is referred toas “X direction”, and a vertical direction is referred to as “Ydirection”.

The light source 10 is a point light source and is configured of a lightemitting diode (LED), specifically. The light source 10 may be enclosedin a package 11 (not illustrated in FIG. 1, see FIG. 2) and may bemounted on a light source substrate 12, for example. The light source 10may face a light incident surface 20A (for example, left and right endfaces in FIG. 1) of the light guide plate 20, for example. The lightsource substrate 12 may have an elongated rectangular-parallelepipedshape and may be arranged in a line in a longitudinal direction thereof,for example.

The light guide plate 20 guides light emitted from the light source 10,from the light incident surface 20A to a light emitting surface 20B. Thelight guide plate 20 may be configured, for example, mainly of atransparent thermoplastic resin such as a polycarbonate resin (PC) andan acrylic resin (such as polymethyl methacrylate (PMMA)). The lightguide plate 20 may have, for example, a rectangular-parallelepiped shapethat is configured of a pair of main surfaces (front and back faces)facing each other in the front-back direction (Z direction) and four endfaces (side faces) adjacent thereto from the top, bottom, left, andright thereof.

Left and right end faces of the light guide plate 20 are each configuredto be the light incident surface 20A on which light emitted from thelight source 10 is incident, as described above. It is to be noted thatonly one of the left and right end faces of the light guide plate 20 maybe configured to be the light incident surface 20A. Alternatively, threeof the end faces of the light guide plate 20 may each be configured tobe the light incident surface 20A. Alternatively, all of the four endfaces may each be configured to be the light incident surface 20A.

The front face and the back face of the light guide plate 20 areconfigured to be light emitting surfaces 20B and 20D that emit lightincident from the light incident surface 20A, respectively. The lightemitting surface 20B (front face) and the light emitting surface 20D(back face) of the light guide plate 20 each have a plane shapecorresponding to an object-to-be-illuminated (such as a liquid crystalpanel 122 described later) that is arranged on the light emittingsurface 20B side of the light guide plate 20.

The light emitting surface 20B (front face) of the light guide plate 20may have, for example, a concavo-convex pattern that is formed of fineconvex sections 20C in order to improve straightness of light thatpropagates in the light guide plate 20. The convex sections 20C may be,for example, strip-like protrusions or ridges that extend in onedirection (for example, in the lateral direction) of the light emittingsurface 20B. The light emitting surface 20D (back face) of the lightguide plate 20 may have, for example, a scattering agent printed thereonin a pattern as a scattering section that scatters light that propagatesin the light guide plate to be uniform. It is to be noted that a sectionthat includes filler may be provided or the surface may be partiallyroughened to provide the scattering section, instead of providing thescattering agent.

The wavelength conversion member 30 converts a wavelength of lightemitted from the light source 10. The wavelength conversion member 30 isprovided between the light source 10 and the light incident surface 20Aof the light guide plate 20. The wavelength conversion member 30 maypreferably include a fluorescent material, for example. Specifically, itis preferable that the light source 10 be a blue light source and thewavelength conversion member 30 include a fluorescent material thatperforms wavelength conversion on blue light from the light source 10 toallow the blue light to be converted into red light or green light.Thus, light of various colors is generated in the light emitting device1 by synthesizing red light and green light resulting from wavelengthconversion by the wavelength conversion member 30.

Moreover, the wavelength conversion member 30 may preferably include aquantum dot, for example. In other words, it is preferable that thelight source 10 be a blue light source and the wavelength conversionmember 30 include a quantum dot that performs wavelength conversion onthe blue light from the light source 10 to allow the blue light to beconverted into red light or green light. The quantum dot has a discreteenergy level and the light emission wavelength is freely selected bychanging the size of the dot. Spectrum of the obtained red and greenlight has a narrow half-band width and a precipitous peak. Therefore,chromatic purity of the red and green light increases and color gamut ofsynthesized light thereof is widened. Accordingly, color gamut isexpanded compared to an existing light emitting device that uses whiteLEDs and a fluorescent material.

The reflection member 40 is a plate-like or sheet-like member that isprovided on the light emitting surface 20D (back face) side of the lightguide plate 20. The reflection member 40 returns, toward the light guideplate 20, light that has been emitted from the light source 10 and hasbeen escaped toward the light emitting surface 20D of the light guideplate or light that has traveled toward the light emitting surface 20Dfrom the inside of the light guide plate 20. The reflection member 40may have functions such as reflection, diffusion, and scattering, forexample. Therefore, it is possible to efficiently utilize light emittedfrom the light source 10 and to increase front luminance.

The reflection member 40 may be configured of, for example, foamed PET(polyethylene terephthalate), a silver-deposited film, a multi-layeredreflection film, or white PET. When the reflection member 40 has aregular reflection (mirror reflection) function, a surface of thereflection member 40 is preferably subjected to a process such as silverdeposition, aluminum deposition, and multilayer reflection. When thereflection member 40 has a fine shape, the reflection member 40 may beintegrally formed by a method such as heat press molding with use of athermoplastic resin and melt extrusion molding. Alternatively, thereflection member 40 may be formed, for example, by applying anenergy-ray (such as ultraviolet ray) curable resin onto a base formed ofa material such as PET, and then, transferring a shape to the energy-raycurable resin. In this example, examples of the thermoplastic resininclude a polycarbonate resin, an acrylic resin such as PMMA (polymethylmethacrylate), a polyester resin such as polyethylene terephthalate, anamorphous copolymerized polyester resin such as MS (copolymer of methylmethacrylate and styrene), a polystyrene resin, and a polyvinyl chlorideresin. Further, the base may be made of glass when a shape istransferred to an energy-ray (such as ultraviolet ray) curable resin.

The optical sheet 50 is provided on the light emitting surface 20B(front face) side of the light guide plate 20. The optical sheet 50 mayinclude, for example, a diffusing plate, a diffusing sheet, a lens film,a polarization separation sheet, and/or the like. FIG. 1 illustratesonly one of the optical sheet 50 configured of the plurality of sheetsdescribed above. Provision of such an optical sheet 50 allows lightemitted from the light guide plate 20 in an oblique direction to travelupward in a front face direction. This further increases frontluminance.

FIG. 2 illustrates an arrangement relationship between the light source10, the light guide plate 20, and the wavelength conversion member 30shown in FIG. 1, and illustrates a cross-section that includes the lightemission center 10A of the light source 10 and is perpendicular to thelight incident surface 20A. The light source 10 is arranged to face thelight incident surface 20A of the light guide plate 20, and thewavelength conversion member 30 is arranged between the light source 10and the light incident surface 20A, as described above. The reflectionmember 40 is laid on the light emitting surface 20D (back face) side ofthe light guide plate 20.

The wavelength conversion member 30 is preferably contained and sealedin a tube-like container (capillary) 31 made of a material such asglass. One reason is that this suppresses a change in characteristics ofthe wavelength conversion member 30 due to moisture, oxygen, or the likein the air and allows the wavelength conversion member 30 to be easilyhandled. It is to be noted that the wavelength conversion member 30 asdescribed above may be manufactured as follows, for example. Afluorescent material or a quantum dot is mixed with an ultraviolet-raycurable resin. The obtained mixture is put into the container 31configured of, for example, a glass tube, and one side of the container31 is sealed. An ultraviolet ray is applied to cure the resin. Thus, agel wavelength conversion member 30 with a certain level of viscosity isformed.

The wavelength conversion member 30 crosses a region S1 that issurrounded by the light incident surface 20A and light paths of light v1and light v2 that travel from the light source 10 and enter edges (anupper edge 20E and an lower edge 20F) of the light incident surface 20A.The wavelength conversion member 30 also extends to a region S2 outsidethe region S1. Thus, evenness of color in a plane is increased in thelight emitting device 1.

The light source 10 and the wavelength conversion member 30 shown inFIG. 2 may be held by a holding member (holder) 60, for example. Theholding member 60 may be configured, for example, of a highly-reflectivepolycarbonate resin or a polyamide-based resin (such as “Genestar (tradename)” available from Kuraray Co., Ltd.). The holding member 60 mayinclude a first holding portion 61 that holds the light source 10 andmay include a second holding portion 62 and a third holding portion 63that hold the wavelength conversion member 30.

The first holding portion 61 is a portion to which the light sourcesubstrate 12 with the light source 10 mounted thereon is attached. Thefirst holding portion 61 faces the light incident surface 20A. Theholding portion 61 includes, in a central part thereof, an opening 61Cthat runs through from an outer face 61A to an inner face 61B. Theopening 61C includes, in a portion thereof closer to the outer face 61A,a seat portion 61D that is formed by recessing a circumference of theopening 61C in a step-like shape. Thus, the seat portion 61D holds thelight source substrate 12, thereby allowing the package 11 provided withthe light source 10 to be loosely set into the opening 61C. It is to benoted that the seat portion 61D may not be necessarily provideddepending on dimensions of the light source substrate 12. Further, apart or all of the inner face 61B is desirably sloped in order toincrease efficiency of utilizing light emitted from the light source 10.

The second holding portion 62 and the third holding portion 63 sandwichupper and lower ends of the container 31 including the wavelengthconversion member 30 to hold the container 31 so that, for example, theposition and the orientation of the container 31 do not change. Thesecond holding portion 62 and the third holding portion 63 may extendfrom an upper end and a lower end of the first holding portion in adirection substantially perpendicular to the first holding portion 61.Therefore, the first holding portion 61, the second holding portion 62,and the third holding portion may have cross-sectional shapes thatconfigure, for example, three sides of a rectangular. The upper andlower ends of the container 31 may be, for example, caught byprotrusions (not illustrated) for holding that are provided in thesecond holding portion 62 and the third holding portion 63. Thus, theupper and lower ends of the container 31 are fixed to the second holdingportion 62 and the third holding portion 63. It is to be noted that theupper and lower ends of the container 31 may be fixed by other methodssuch as using a double-faced adhesive tape.

Moreover, a tip end of the second holding portion 62 and a tip end ofthe third holding portion 63 sandwich and hold an end of the light guideplate 20 and an end of the reflection member 40. It is to be noted thatit is enough that the second holding portion 62 and the third holdingportion 63 sandwich at least the upper and lower ends of the container31. The end of the light guide plate 20 and the end of the reflectionmember 40 may be held by other members (which will be described later).

It is to be noted that a not-illustrated heat dissipation member (heatspreader) is attached to the outside of the above-described holdingmember 60, in particular, around the light source 10. Moreover, thelight emitting device 1 as a whole that includes components such as thelight source 10, the light guide plate 20, the wavelength conversionmember 30, the reflection member 40, the optical sheet 50, and theholding member 60, and the heat dissipation member (not illustrated) iscontained in a chassis which is not illustrated (not illustrated inFIGS. 1 and 2, see a back chassis 124 in FIG. 15, for example).

In the light emitting device 1, light emitted from the light source 10is subjected to wavelength conversion in the wavelength conversionmember 30, enters the light incident surface 20A of the light guideplate 20, travels through the inside of the light guide plate 20, exitsfrom the light emitting surface 20B, and passes through the opticalsheet 50. This is observed as light emission.

Here, the light source 10 is a point light source as described above.Therefore, light emitted from the light source 10 is spread from thelight emission center 10A in all directions of 360° around. There is notany special issue in light spreading in the lateral direction since thewavelength conversion member 30 and the light incident surface 20Aextend in the lateral direction as shown in FIG. 3. On the other hand,part of light spread in the vertical direction may deviate to a regionabove the upper edge 20E or may deviate to a region below the lower edge20F.

Here, the wavelength conversion member 30 crosses the region S1 that issurrounded by the light incident surface 20A and the light paths of thelight v1 and the light v2 that are emitted from the light source 10 andenter the edges (the upper edge 20E and the lower edge 20F) of the lightincident surface 20A. In other words, the wavelength conversion memberintersects with (crosses) the region S1 in a direction parallel to thelight incident surface 20A. Therefore, light that passes through theinside of the region S1 and enters the light incident surface 20A issubjected to wavelength conversion in the wavelength conversion member30.

Moreover, the wavelength conversion member 30 extends to the region S2outside the region S1. In other words, the wavelength conversion member30 is provided to spread over and out of the region S1 and to extend inthe region S2 outside thereof. Therefore, light that is emitted from thelight source 10 and spreads in the vertical direction to travel outsidethe region S1 is caught by the wavelength conversion member 30 in acertain degree and is subjected to wavelength conversion. Accordingly,in the light emitting device 1, light that does not pass through thewavelength conversion member 30 out of the light emitted from the lightsource 10, namely, light that is not subjected to wavelength conversionin the wavelength conversion member 30 is reduced. Therefore, evennessof color in a plane is improved.

As described above, in the present embodiment, the wavelength conversionmember 30 crosses the region S1 that is surrounded by the light incidentsurface 20A and the light paths of the light v1 and the light v2 thatare emitted from the light source 10 and enter the edges (the upper edge20E and the lower edge 20F) of the light incident surface 20A. Inaddition thereto, the wavelength conversion member 30 extends to theregion S2 outside the region S1. This reduces light that does not passthrough the wavelength conversion member 30 out of the light emittedfrom the light source 10, namely, light that is not subjected towavelength conversion in the wavelength conversion member 30. Thus,evenness of color in a plane is increased.

Second Embodiment

FIG. 4 illustrates a cross-sectional configuration of a light emittingdevice 1A according to a second embodiment of the present invention. Thelight emitting device 1A includes a light shielding member 70 betweenthe light incident surface 20A of the light guide plate 20 and thecontainer 31 which includes the wavelength conversion member 30. Thus,color unevenness that occurs in the vicinity of the light incidentsurface 20A is reduced and evenness of color in a plane is furtherincreased. Except for this, the light emitting device 1A has aconfiguration, functions, and effects that are similar to those in thefirst embodiment. Therefore, the corresponding components are describedwith the same numerals.

The light source 10, the package 11, the light source substrate 12, thelight guide plate 20, the wavelength conversion member 30, the container31, the reflection member 40, and the optical sheet 50 each have aconfiguration similar to that in the first embodiment.

The holding member 60 includes the first holding portion 61 that holdsthe light source 10, and includes the second holding portion 62 and thethird holding portion 63 that hold the wavelength conversion member 30,as in the first embodiment.

The holding portion 61 includes, in a central part thereof, the opening61C that runs through from the outer face 61A to the inner face 61B. Inthe present embodiment, the seat portion 61D on the outer face 61A sideof the opening 61C is not provided. The light source substrate 12 isfixed to the outer face 61A, and thereby, the package 11 with the lightsource 10 mounted thereon is loosely set into the opening 61C.

The second holding portion 62 holds, with the third holding portion 63,the upper end of the container 31 including the wavelength conversionmember 30. It is to be noted that FIG. 4 illustrates a case in which theoptical sheet 50 is arranged on the light emitting surface 20B of thelight guide plate 20, and an end of the optical sheet 50 is held not bythe second holding portion 62 but by a frame-like member 80 (see FIG.15). The frame-like member 80 is a frame-like resin component that holdsthe optical sheet 50, which is a so-called middle chassis.

The third holding portion 63 holds, with the second holding portion 62,the lower end of the container 31 including the wavelength conversionmember 30. The tip end of the third holding portion 63 extends on theback side of the light emitting surface 20D (back face) of the lightguide plate 20 and of the reflection member 40.

The light shielding member 70 is provided on a light path of light v3that is emitted from the light source 10, passes through the container31 without passing through the wavelength conversion member 30, andtravels toward a surface adjacent to the light incident surface 20A ofthe light guide plate 20, namely, toward the light emitting surface 20Bor the light emitting surface 20D.

In other words, when the light shielding member 70 is not provided, thelight v3 may pass through a space near the holding member 60, theframe-like member 80, etc., to enter the optical sheet 50, and may beemitted directly to the outside, as shown in FIG. 5. In this case, thelight v3 is not subjected to wavelength conversion in the wavelengthconversion member 30. Also, the light v3 is not mixed, in the lightguide plate 20, with green or red light resulting from wavelengthconversion. Therefore, the light v3 is emitted as blue light which is ina state unchanged from that at the time when the light v3 is emittedfrom the light source 10. Accordingly, blue color unevenness B caused bythe light v3 is observed along right and left sides in which the lightsource 10 is provided, when the light emitting device 1 is seen from thefront side of the optical sheet 50, as schematically shown in FIG. 6.

The light v3 that causes the above-described color unevenness B isemitted from a portion 31A of the container 31. When specific valuesconcerning dimensions and location relationship between the light source10, the light guide plate 20, and the wavelength conversion member 30are given, the portion 31A is specified based on the given specificvalues. For example, as shown in FIG. 7, a dimension t1 from the upperend to the lower end of the container 31 may be 4 mm, a thickness t2 ofthe light guide plate 20 may be 3.5 mm, and a maximum thickness t3 ofthe wavelength conversion member 30 may be 2.7 mm. For example, adistance L1 between the light emission center 10A of the light source 10and the container 31 may be 0.6 mm, a thickness L2 of the container 31in the lateral direction may be 2 mm, and a distance L3 between thecontainer 31 and the light incident surface 20A may be 1.4 mm. Forexample, a thickness (difference between the outer diameter and an innerdiameter) R of the container 31 may be 1 mm, and a refractive index N ofthe container 31 may be 1.51.

In this case, the portion 31A from which the light v3 causing the colorunevenness B is emitted is limited in a range that has a distance L from1.95 nm to 2.16 nm both inclusive from the light emission center 10A ofthe light source 10 in the lateral direction, and that has a distance tfrom 1.83 mm to 1.94 mm both inclusive in a height direction, as shownin FIG. 8. Therefore, the light shielding member 70 is provided based onthe above-described calculation to shield the light v3 and to suppressthe color unevenness B. It is to be noted that the portion 31A fromwhich the light v3 causing the color unevenness B is emitted isillustrated with a line thicker than an outline of the container 31 inFIG. 8.

In particular, the light shielding member 70 is preferably a lightshielding protrusion 71 that is provided in each of the second holdingportion 62 and the third holding portion 63 of the holding member 60, asshown in FIG. 4. Thus, the light v3 is shielded at a position extremelyclose to the portion from which the light v3 causing the colorunevenness B is emitted. This securely suppresses occurrence of thecolor unevenness B. In addition thereto, this allows easy formation ofthe light shielding member 70 in a process of manufacturing the holdingmember 60 which is configured of a resin component.

Alternatively, it is also preferable that the light shielding member 70be a light shielding protrusion 72 that is provided in the frame-likemember 80 as shown in a light emitting device 1B in FIG. 9. This allowseasy formation of the light shielding member 70 in a process ofmanufacturing the frame-like member 80 which is configured of a resincomponent.

Alternatively, it is also preferable that the light shielding member 70be a light shielding cushion 73 that covers an end of a surface adjacentto the light incident surface 20A of the light guide plate 20, inparticular, that covers an end of the light emitting surface 20B, asshown in a light emitting device 1C in FIG. 10. In this case, unlikeproviding the light shielding protrusion 71 or 72 shown in FIG. 4 or 9,it is possible to suppress reflection of light due to the lightshielding protrusion 71 or 72. Thus, it is possible to further increaseefficiency of utilizing light. Moreover, the light shielding cushion 73is preferably sandwiched between the frame-like member 80 and the lightemitting surface 20B of the light guide plate 20. This allows to adjustmechanical clearance between the frame-like member 80 and the lightguide plate 20, or allows to reduce sounds which are made when theframe-like member 80 touches the light guide plate 20 made of a materialdifferent from that of the frame-like member 80. It may be preferable touse, for example, urethane foam (“PORON (registered trademark)”available from Rogers Inoac Corporation) as a material that configuresthe light shielding cushion 73.

In addition thereto, it is more preferable that the optical sheet 50 beprovided on the opposite side of the frame-like member 80 from the lightshielding cushion 73 (above the frame-like member 80, that is, in thefront (closer to the light emission observation surface)), as shown in alight emitting device 1D in FIG. 11. One reason is that this allows awidth of the light shielding cushion 73 to be wider than that in FIG.10, thereby allowing easy attachment of the light shielding cushion 73.

Moreover, it is also preferable to provide a lower cushion 74 on thelight emitting surface 20D (back face) side of the light guide plate 20,specifically, between the reflection member 40 and the third holdingportion 63 of the holding member 60, as shown in a light emitting device1E in FIG. 12. This shields light that is emitted from the light source10, passes through the container 31 without passing through thewavelength conversion member 30, and travels toward a surface adjacentto the light incident surface 20A of the light guide plate 20, namely,toward the light emitting surface 20D. This suppresses color unevennesscaused by this light. Also, the lower cushion 74 has not only the lightshielding function but also functions such as clearance adjustment andabnormal noise prevention as the light shielding cushion 73 describedabove. For example, polyethylene foam (“SUPER OPCELL (registeredtrademark)” available from Sanwa Kako Co., Ltd.) may be preferable as amaterial that configures the lower cushion 74.

In addition thereto, it is preferable that an end of the reflectionmember 40 extend over and out of the light guide plate 20 toward thelight source 10 as shown in FIGS. 4 and 9 to 12. This shields light thatis emitted from the light source 10, passes through the container 31without passing through the wavelength conversion member 30, and travelstoward a surface adjacent to the light incident surface 20A of the lightguide plate 20, namely, toward the light emitting surface 20D. Thus,color unevenness caused by this light is suppressed. Moreover, a highereffect is further obtained when the light shielding protrusion 71 of thethird holding portion 63 shown in FIG. 4 is used together or when thelower cushion 74 shown in FIG. 12 is used together.

In each of the light emitting devices 1A to 1E, as in the firstembodiment, light emitted from the light source is subjected towavelength conversion in the wavelength conversion member 30, enters thelight incident surface 20A of the light guide plate 20, travels throughthe inside of the light guide plate 20, exits from the light emittingsurface 20B, and passes through the optical sheet 50. This is observedas light emission.

At this time, the light v3 that is emitted from the light source 10,passes through the container 31 without passing through the wavelengthconversion member 30, and travels toward the surface (the light emittingsurface 20B or the light emitting surface 20D) adjacent to the lightincident surface 20A of the light guide plate 20 is generated. The lightv3 may pass through the space near the holding member 60, the frame-likemember 80, etc., passes through the optical sheet 50, and may be emitteddirectly to the outside. This light v3 may cause the blue colorunevenness B as shown in FIG. 6. In the present embodiments, the lightshielding member 70 is provided on the light path of the light v3.Therefore, the light v3 that causes the color unevenness B is shieldedby the light shielding member 70. Accordingly, evenness of color in aplane is further improved.

It is to be noted that there is light v4 that is emitted from the lightsource 10, passes through the container 31 without passing through thewavelength conversion member 30, passes through the space near theholding member 60, the frame-like member 80, etc., and enters the lightincident surface 20A of the light guide plate 20, as shown in FIGS. 4and 9 to 12. However, the light v4 is mixed, in the light guide plate20, with light which has been subjected to wavelength conversion.Therefore, the light v4 is less likely to cause a significant issue suchas color unevenness B caused by the light v3. Also, when the light v3enters the light emitting surface 20B or 20D of the light guide plate20, the light v3 is mixed, in the light guide plate 20, with light whichhas been subjected to wavelength conversion. Thus, the issue of colorunevenness B is moderated.

As described above, in the present embodiments, the light shieldingmember 70 is provided on the light path of the light v3 that is emittedfrom the light source 10, passes through the container 31 withoutpassing through the wavelength conversion member 30, and travels towardthe surface adjacent to the light incident surface 20A of the lightguide plate 20, namely, toward the light emitting surface 20B or thelight emitting surface 20D. Therefore, the light v3 that causes colorunevenness is shielded. Accordingly, evenness of color in a plane isfurther improved.

Third Embodiment

FIG. 13 illustrates an appearance of a display unit 101 according to athird embodiment of the present disclosure. The display unit 101 may beused, for example, as a flat-screen television unit. The display unit101 has a configuration in which a stand 103 holds a flat-plate-likemain body section 102 for image display. The display unit 101 is used asa standing display unit that is placed on a horizontal surface such as afloor, a shelf, and a rack in a state where the stand 103 is attached tothe main body section 102. However, it is to be noted that the displayunit 101 may be used as a wall-hanging display unit in a state where thestand 103 is removed from the main body section 102.

FIG. 14 illustrates an exploded view of the main body section 102 shownin FIG. 13. The main body section 102 may include, for example, a frontexterior member (bezel) 111, a panel module 112, and a back exteriormember (rear cover) 113 in this order of closeness to a front face (to aviewer). The front exterior member 111 is a picture-frame-like memberthat covers front circumference of the panel module 112. A pair ofspeakers 114 are arranged in a lower part of the front exterior member111. The panel module 112 is fixed to the front exterior member 111. Anelectric power source substrate 115 and a signal substrate 116 aremounted on a back face of the panel module 112 and an attachment bracket117 is fixed thereto. The attachment bracket 117 is for attachment of awall-hanging bracket, for attachment of components such as a substrate,and for attachment of the stand 103. The back exterior member 113 coversthe back face and side faces of the panel module 112.

FIG. 15 illustrates an exploded view of the panel module 112 shown inFIG. 13. The panel module 112 may include, for example, a front housing(top chassis) 121, a liquid crystal panel 122, the frame-like member(middle chassis) 80, the optical sheet 50, the light guide plate 20, thereflection member 40, a back housing (back chassis) 124, a balancersubstrate 125, a balancer cover 126, and a timing controller substrate127 in this order of closeness to the front face (to the viewer).

The front housing 121 is a frame-like metal component that covers frontcircumference of the liquid crystal panel 122. The liquid crystal panel122 may include, for example, a liquid crystal cell 122A, a sourcesubstrate 122B, and a flexible substrate 122C such as COF (chip on film)that connects the liquid crystal cell 122A and the source substrate122B. The frame-like member 80 is a frame-like resin component thatholds the liquid crystal panel 122 and the optical sheet 50. The backhousing 124 is a component made of metal such as iron (Fe) and containsthe liquid crystal panel 122, the frame-like member 80, and the lightemitting device 1. The balancer substrate 125 controls the lightemitting device 1. The balancer substrate 125 is mounted on a back faceof the back housing 124 and is covered with the balancer cover 126, asshown in FIG. 15. The timing controller substrate 127 is also mounted onthe back face of the back housing 124.

In the display unit 101, light emitted from the light emitting device 1is selectively transmitted by the liquid crystal panel 122, and an imageis displayed thereby. In the present example, the display unit 101includes the light emitting device 1 that has improved color evenness ina plane as described in the first embodiment. Therefore, display qualityof the display unit 101 is improved.

It is to be noted that, although a case in which the display unit 101includes the light emitting device 1 according to the first embodimentis described above in the third embodiment, it goes without saying thatthe display unit 101 may include any of the light emitting devices 1A to1E according to the second embodiment instead of the light emittingdevice 1 according to the first embodiment.

[Application Examples of Display Unit]

Examples in which the above-described display unit 101 is applied toelectronic apparatuses will be described below. Examples of theelectronic apparatus include televisions, digital cameras, notebookpersonal computers, personal digital assistants such as mobile phones,and video camcorders. In other words, the above-described display unitis applicable to an electronic apparatus in any filed that uses anexternally-inputted or internally-generated image signal to display animage or a moving picture.

Application Example 1

FIGS. 16A and 16B each illustrate an appearance of an electronic book towhich the display unit 101 of the above-described embodiment is applied.The electronic book may include, for example, a display section 210 anda non-display section 220. The display section 210 is configured of thedisplay unit 101 of the above-described embodiment.

Application Example 2

FIG. 17 illustrates an appearance of a smartphone to which the displayunit 101 of the above-described embodiment is applied. The smartphonemay include, for example, a display section 230 and a non-displaysection 240. The display section 230 is configured of the display unit101 of the above-described embodiment.

Application Example 3

FIG. 18 illustrates an appearance of a digital camera to which thedisplay unit 101 of the above-described embodiment is applied. Thedigital camera may include, for example, a light emitting section 410for a flash, a display section 420, and a menu switch 430, and a shutterbutton 440. The display section 420 is configured of the display unit101 of the above-described embodiment.

Application Example 4

FIG. 19 illustrates an appearance of a notebook personal computer towhich the display unit 101 of the above-described embodiment is applied.The notebook personal computer may include, for example, a main body510, a keyboard 520 for operations of inputting characters etc., and adisplay section 530 that displays an image. The display section 530 isconfigured of the display unit 101 of the above-described embodiment.

Application Example 5

FIG. 20 illustrates an appearance of a video camcorder to which thedisplay unit 101 of the above-described embodiment is applied. The videocamcorder may include, for example, a main body section 610, a lens 620for shooting an object that is provided in a front side face of the mainbody section 610, a start-stop switch 630 used in shooting, and adisplay section 640. The display section 640 is configured of thedisplay unit 101 of the above-described embodiment.

Application Example 6

FIGS. 21A to 21G each illustrate an appearance of a mobile phone towhich the display unit 101 of the above-described embodiment is applied.The mobile phone may be configured, for example, of a top housing 710and a bottom housing 720 that are connected by a connection section(hinge section) 730. The mobile phone may include, for example, adisplay 740, a sub-display 750, a picture light 760, and a camera 770.One or both of the display 740 and the sub-display 750 are eachconfigured of the display unit 101 of the above-described embodiment.

[Application Example of Illumination Unit]

FIGS. 22 and 23 each illustrate an appearance of a desk illuminationunit to which any of the light emitting devices 1 and 1A to 1E of theabove-described embodiments is applied. The illumination unit mayinclude, for example, a post 842 that is provided on a base 841 and anillumination section 843 that is attached to the post 842. Theillumination section 843 is configured of any of the light emittingdevices 1 and 1A to 1E according to the above-described first and secondembodiments. The illumination section 843 may have any shape such as arolled shape shown in FIG. 22 and a curved-face shape shown in FIG. 23,by allowing the light guide plate 20 to have a curved shape.

FIG. 24 illustrates an appearance of a room illumination unit to whichany of the light emitting devices 1 and 1A to 1E of the above-describedembodiments is applied. The illumination unit may include, for example,an illumination section 844 that is configured of any of the lightemitting devices 1 and 1A to 1E according to the above-describedembodiments. The illumination sections 844 are arranged in theappropriate number at an appropriate interval on a sealing 850A of abuilding. It is to be noted that the illumination section 844 is notlimitedly provided on the sealing 850A and may be provided in any placesuch as on a wall 850B and on a floor (not illustrated) according to theapplication.

The illumination unit performs illumination with use of light emittedfrom the light emitting device 1. In the present example, theillumination unit includes the light emitting device 1 with improvedcolor evenness in a plane as described in the first embodiment.Therefore, illumination quality is improved.

Hereinbefore, the present disclosure has been described with referenceto the preferred embodiments. However, the present disclosure is notlimited to the above-described embodiments and may be variouslymodified. For example, the material, the thickness, etc. of each layerdescribed above in the embodiments are not limitative and othermaterials, other thicknesses, etc. may be used.

Moreover, for example, although a case in which the light source 10 isan LED has been described above in the embodiments, the light source 10may be configured of a component such as a semiconductor laser.

Moreover, for example, the configurations of the light emitting devices1 and 1A to 1E and the display unit 101 (television unit) have beendescribed above with specific examples in the embodiments. However, itis not necessary to include all of the components and other componentsmay be further included.

In addition thereto, a case in which the wavelength conversion member 30is sealed in the container 31 has been described above in theembodiments. However, the wavelength conversion member 30 may be asheet-like member in which a fluorescent material or a quantum dot isdispersed in a resin sheet.

Moreover, the edge-light type light emitting device 1 in which lightemitted from the light source 10 is guided to the light incident surface20A which is the end face of the light guide plate 20 and is emittedfrom the light emitting surface 20B toward the front face has beendescribed above in the embodiment. However, the present disclosure isalso applicable to a direct type light emitting device in which thelight source 10 is arranged in a plane and a diffuser is arranged as anoptical component above the light source 10.

It is possible to achieve at least the following configurations from theabove-described example embodiments and the modifications of thedisclosure.

-   -   (1) A light emitting device including:        a light source;        an optical component including a light incident surface, the        light incident surface facing the light source; and        a wavelength conversion member provided between the light source        and the light incident surface, the wavelength conversion member        crossing a first region and extending to a second region outside        the first region, the first region being surrounded by the light        incident surface and light paths of light that is emitted from        the light source and enters edges of the light incident surface.    -   (2) The light emitting device according to (1), further        including        a container containing the wavelength conversion member.    -   (3) The light emitting device according to (2), further        including

a light shielding member provided on a light path of light that isemitted from the light source, passes through the container withoutpassing through the wavelength conversion member, and travels toward asurface adjacent to the light incident surface of the optical component.

-   -   (4) The light emitting device according to (3), wherein the        light shielding member is a light shielding cushion covering an        end of the surface adjacent to the light incident surface of the        optical component.    -   (5) The light emitting device according to (4), further        including:

an optical sheet provided on the surface adjacent to the light incidentsurface of the optical component; and

a frame-like member holding the optical sheet, wherein

the light shielding cushion is sandwiched between the frame-like memberand the optical component.

-   -   (6) The light emitting device according to (5), wherein the        optical sheet is provided on an opposite side of the frame-like        member from the light shielding cushion.    -   (7) The light emitting device according to (3), further        including

a holding member holding the container, wherein

the light shielding member is a light shielding protrusion that isprovided on the holding member.

-   -   (8) The light emitting device according to (3), further        including

an optical sheet provided on the surface adjacent to the light incidentsurface of the optical component; and

a frame-like member holding the optical sheet, wherein

the light shielding member is a shielding protrusion provided on theframe-like member.

-   -   (9) The light emitting device according to any one of (1) to        (8), wherein the light source is a point light source.    -   (10) The light emitting device according to any one of (1) to        (9), wherein the wavelength conversion member includes a        fluorescent material.    -   (11) The light emitting device according to (1), wherein the        wavelength conversion member includes a quantum dot.    -   (12) The light emitting device according to any one of (1) to        (11), wherein the light source is a blue light source.    -   (13) The light emitting device according to (12), wherein the        light source is configured of a light emitting diode.    -   (14) The light emitting device according to any one of (1) to        (13), wherein

the optical component is a light guide plate, and

the light incident surface is an end face of the light guide plate.

-   -   (15) A display unit with a liquid crystal panel and a light        emitting device on a back face side of the liquid crystal panel,        the light emitting device including:        a light source;

an optical component including a light incident surface,

the light incident surface facing the light source; and

a wavelength conversion member provided between the light source and thelight incident surface, the wavelength conversion member crossing afirst region and extending to a second region outside the first region,the first region being surrounded by the light incident surface andlight paths of light that is emitted from the light source and entersedges of the light incident surface.

-   -   (16) An illumination unit with a light emitting device, the        light emitting device including:        a light source;

an optical component including a light incident surface,

the light incident surface facing the light source; and

a wavelength conversion member provided between the light source and thelight incident surface, the wavelength conversion member crossing afirst region and extending to a second region outside the first region,the first region being surrounded by the light incident surface andlight paths of light that is emitted from the light source and entersedges of the light incident surface.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A light emitting device comprising: a lightsource; an optical component including a light incident surface, thelight incident surface facing the light source; and a wavelengthconversion member to convert a wavelength of at least a portion of lightemitted from the light source from a first wavelength to a secondwavelength which is different from the first wavelength, said wavelengthconversion member being provided between the light source and the lightincident surface, the wavelength conversion member crossing a firstregion and extending to a second region outside the first region, thefirst region being surrounded by the light incident surface and lightpaths of light that is emitted from the light source and enters edges ofthe light incident surface, the light source is a blue light source, andthe wavelength conversion member is configured to convert the wavelengthof at least the portion of the blue light emitted from the blue lightsource from the first wavelength which corresponds to the blue light tothe second wavelength which corresponds to either red light or greenlight, so as to convert the blue light into either the red light or thegreen light.
 2. The light emitting device according to claim 1, furthercomprising a container containing the wavelength conversion member. 3.The light emitting device according to claim 2, further comprising alight shielding member provided on a light path of light that is emittedfrom the light source, passes through the container without passingthrough the wavelength conversion member, and travels toward a surfaceadjacent to the light incident surface of the optical component.
 4. Thelight emitting device according to claim 3, wherein the light shieldingmember is a light shielding cushion covering an end of the surfaceadjacent to the light incident surface of the optical component.
 5. Thelight emitting device according to claim 4, further comprising: anoptical sheet provided on the surface adjacent to the light incidentsurface of the optical component; and a frame-like member holding theoptical sheet, wherein the light shielding cushion is sandwiched betweenthe frame-like member and the optical component.
 6. A light emittingdevice comprising: a light source; an optical component including alight incident surface, the light incident surface facing the lightsource; a wavelength conversion member provided between the light sourceand the light incident surface, the wavelength conversion membercrossing a first region and extending to a second region outside thefirst region, the first region being surrounded by the light incidentsurface and light paths of light that is emitted from the light sourceand enters edges of the light incident surface; a container containingthe wavelength conversion member; and a light shielding member providedon a light path of light that is emitted from the light source, passesthrough the container without passing through the wavelength conversionmember, and travels toward a surface adjacent to the light incidentsurface of the optical component, wherein the light shielding member isa light shielding cushion covering an end of the surface adjacent to thelight incident surface of the optical component, further comprising: anoptical sheet provided on the surface adjacent to the light incidentsurface of the optical component; and a frame-like member holding theoptical sheet, wherein the light shielding cushion is sandwiched betweenthe frame-like member and the optical component, and wherein the opticalsheet is provided on an opposite side of the frame-like member from thelight shielding cushion.
 7. A light emitting device comprising: a lightsource; an optical component including a light incident surface, thelight incident surface facing the light source; a wavelength conversionmember provided between the light source and the light incident surface,the wavelength conversion member crossing a first region and extendingto a second region outside the first region, the first region beingsurrounded by the light incident surface and light paths of light thatis emitted from the light source and enters edges of the light incidentsurface; a container containing the wavelength conversion member; alight shielding member provided on a light path of light that is emittedfrom the light source, passes through the container without passingthrough the wavelength conversion member, and travels toward a surfaceadjacent to the light incident surface of the optical component; and aholding member holding the container, wherein the light shielding memberis a light shielding protrusion that is provided on the holding member.8. The light emitting device according to claim 3, further comprising anoptical sheet provided on the surface adjacent to the light incidentsurface of the optical component; and a frame-like member holding theoptical sheet, wherein the light shielding member is a shieldingprotrusion provided on the frame-like member.
 9. The light emittingdevice according to claim 1, wherein the light source is a point lightsource.
 10. The light emitting device according to claim 1, wherein thewavelength conversion member includes a fluorescent material.
 11. Thelight emitting device according to claim 1, wherein the wavelengthconversion member includes a quantum dot.
 12. The light emitting deviceaccording to claim 1, wherein the light source is configured of a lightemitting diode.
 13. The light emitting device according to claim 1,wherein the optical component is a light guide plate, and the lightincident surface is an end face of the light guide plate.
 14. A displayunit with a liquid crystal panel and a light emitting device on a backface side of the liquid crystal panel, the light emitting devicecomprising: a light source; an optical component including a lightincident surface, the light incident surface facing the light source;and a wavelength conversion member to convert a wavelength of at least aportion of light emitted from the light source from a first wavelengthto a second wavelength which is different from the first wavelength,said wavelength conversion member being provided between the lightsource and the light incident surface, the wavelength conversion membercrossing a first region and extending to a second region outside thefirst region, the first region being surrounded by the light incidentsurface and light paths of light that is emitted from the light sourceand enters edges of the light incident surface, the light source is ablue light source, and the wavelength conversion member is configured toconvert the wavelength of at least the portion of the blue light emittedfrom the blue light source from the first wavelength which correspondsto the blue light to the second wavelength which corresponds to eitherred light or green light, so as to convert the blue light into eitherthe red light or the green light.
 15. An illumination unit with a lightemitting device, the light emitting device comprising: a light source;an optical component including a light incident surface, the lightincident surface facing the light source; and a wavelength conversionmember to convert a wavelength of at least a portion of light emittedfrom the light source from a first wavelength to a second wavelengthwhich is different from the first wavelength, said wavelength conversionmember being provided between the light source and the light incidentsurface, the wavelength conversion member crossing a first region andextending to a second region outside the first region, the first regionbeing surrounded by the light incident surface and light paths of lightthat is emitted from the light source and enters edges of the lightincident surface, the light source is a blue light source, and thewavelength conversion member is configured to convert the wavelength ofat least the portion of the blue light emitted from the blue lightsource from the first wavelength which corresponds to the blue light tothe second wavelength which corresponds to either red light or greenlight, so as to convert the blue light into either the red light or thegreen light.